HeatFREE wheels are especially useful in preparing contrast finishes and texturing—much coarser than a brushed satin finish. Also often used for fast grinding and metal removal such as cleaning up casting sprues, because these very hard wheels are made of silicon carbide in a resinoid bond. HeatFREE Wheels break down steadily so they are constantly exposing new grit which allows them to produce a uniform, coarse, brushed-look finish with tiny highlights. Easily shaped with a file if desired. 1/16" metal arbor hole. Maximum operating speed: 25,000rpm. Sold in packages of 10. Made in Mexico.